Abstract

SUMMARY Raspberries are highly adaptable to different growing conditions and soils, but ideal conditions are well fertilized soils with a pH of 5.5-6. Since raspberries are perennials with the fruit developing on last year´s laterals, this has to be considered when managing and fertilizing the plants. The size of the raspberry crop is mainly decided during the first year of growing when the fruit buds are developed, but can be effected by the environment and pruning during year two. Primocanes and floricanes are competing for light, which can be controlled by different methods of pruning. The plants need for the nutrients vary during the growing season as does the uptake ability, but most of the uptake takes places during spring with a peak in June/July. The vegetative primocanes and the generative floricanes have different nutrition needs. For the vegetative growth primarily nitrogen is needed, but for the fruit development potassium is most important. The plants distribute the nutrients to different parts based on the current need. When applied at budbreak, most of the nitrogen is distributed to fruit, fruitbuds and primocanes. When applied two months after budbreak, most of the nitrogen is used for primocane growth. The vegetative growth continues throughout the whole growing season until October. A general, long term fertilizing schedule could be designed as follows: Nitrogen 60-100 kg/ha, from spring to harvest; Phosphorus 20-40 kg/ha, spring; Potassium 80-120 kg/ha, spring, June, September; Magnesium 12-15 kg/ha, before, during and after flowering, after harvest Micronutrients should be applied as a foliar spray to avoid binding of the nutrients to the soil, and should be based on foliar nutrient analysis.